Date Published: June 22, 2010
Publisher: Public Library of Science
Author(s): Ted Cohen, Megan Murray, Kristina Wallengren, Gonzalo G. Alvarez, Elizabeth Y. Samuel, Douglas Wilson, Neil A. Martinson
Abstract: A postmortem study by Ted Cohen and colleagues reveals a huge toll of tuberculosis among patients dying in hospitals in KwaZulu-Natal, South Africa.
Partial Text: The emergence of HIV in South Africa has resulted in a dramatic rise in the incidence of tuberculosis (TB). Between 1990 and 2007, as the adult HIV prevalence rose to 18.1%  the incidence of tuberculosis increased more than 3-fold from 301 to 948 cases/100,000 persons/year . Approximately 80% of incident TB cases in South Africa are HIV-seropositive . These coinfected individuals are more likely to have sputum smear–negative pulmonary or extrapulmonary TB ,, which can be difficult to diagnose clinically. The World Health Organization recommends mycobacterial culture for patients diagnosed with sputum smear–negative tuberculosis. However, the utility of this investigation is limited by cost and long laboratory turn-around times.
Two hundred and forty decedents were recruited into the study with dates of death beginning on 28 October 28 2008 and ending on 12 August 12 2009. Over this entire time period, a total of 997 deaths occurred among inpatients who were eligible for inclusion in the study. Table 1 displays selected characteristics of individuals included in this sample. We found no significant difference in the age and sex distribution of those included in the sample and those eligible to be in the sample. The median age was 33 y with an interquartile range (IQR) of 28–38 y for those actually included in the study and also 33 y (IQR 28–38 y) for those eligible to be in the study, p = 0.31; the sex distribution was 44% male in the study compared with 46% male among those eligible to be in the study) (p = 0.60). Two hundred and twenty six (94%) of the decedents in the study were HIV-positive; 200 of the seropositive individuals had been diagnosed with HIV before death. As such, the apparent HIV prevalence (not including those whose HIV infections were diagnosed after death) among those included in the study (200/240 = 83%) was not statistically significantly different than the observed HIV prevalence among a random selection of eligible decedents who were not included in the study (126/164 = 77%; p = 0.13). In total, 17% of HIV-positive decedents included in the study were receiving antiretroviral therapy at the time of death; of the subset of participants known to be HIV positive before autopsy, 20% were receiving antiretroviral drugs. Antiretroviral usage was lower among participants than among the random selection of known HIV positive decedents that were not included in the study (38/126 = 30%; p-value = 0.03). 15% of decedents had at least one previous hospitalization within the past 6 mo. Decedents died a median of 4 d (IQR 1–7 d) after admission to the hospital.
While TB is recognized as a major cause of early death in KwaZulu-Natal, South Africa, our findings reveal that the toll of TB is far larger than has been previously reported. Despite efforts to prioritize diagnosis and treatment of TB, especially among those coinfected with HIV, we found that half of the inpatients who died at a single hospital had evidence of TB at the time of death. Although almost half of those who died were on TB treatment at the time of death, more than half of those on treatment still had evidence of viable M. tuberculosis in their postmortem specimens. Nearly half of the decedents who were not on TB treatment at the time of death also had evidence of TB. Since needle core biopsies of organs and respiratory specimens are unlikely to detect all cases of disease, the proportion of decedents from which we could grow M. tuberculosis should be considered a minimum estimate of the actual fraction with TB at the time of death.